1. Field of the Invention
The present invention relates to an optical module for use in optical communication.
2. Description of the Related Art
An optical module of this kind has an optical semiconductor device contained in a package, and the optical semiconductor device is optically connected to an optical fiber via an optical system. The optical semiconductor device is operated by supplying electric power, and it can emit and receive laser light through the optical system and the optical fiber.
The operating characteristic of the optical semiconductor device is easily affected by the thermal effect. Therefore, it is important for the optical module to effectively restrain the variation in the operating characteristic of the optical semiconductor device inside due to the heat generated in its operation. For the stabilization of the operating characteristic of the semiconductor device against the temperature fluctuation, the method of forcible cooling using a thermo-module, which comprises a Peltier device, for example, and the method of natural cooling using a heat sink are available. From the standpoint of the power saving, the method using a heat sink is preferable.
On the other hand, in respect of the optical communication equipments using the optical module such as an optical amplifier and a signal light source, the reduction in the entire size thereof is required. Thus, the reduction in the mounting size of the individual optical modules is also required. For example, when employing the insertion mounting (also referred to as a xe2x80x9cthrough hole mountingxe2x80x9d) in which an optical module is inserted into a wiring board, the so-called DIL (dual in-line) package is suitable to achieve the reduction in the mounting size. In the DIL package, several pairs of lead pins are provided on both the sides of the package and each of the lead pins extends downward from the side surface. Therefore, if the optical module is mounted with the lead pins being inserted in the through hole of the wiring board, the lead pins do not spread in the lateral direction. Therefore, the mounting area thereof can be reduced.
On the other hand, the heat generated in the optical module is usually radiated to the outside of the package through its bottom surface serving as a heat radiation path. In the DIL package, however, since the lead pins are protruded downward, it is difficult to arrange the heat sink or the like immediately below the package. Therefore, it is generally difficult to adopt the cooling method using the heat sink or the like in the DIL package.
The present invention disclosed and claimed herein, in one aspect thereof, comprises an optical module. The optical module comprises a package which contains an optical semiconductor device optically connected to an optical fiber via an optical system, the package having a bottom surface to be faced to a predetermined wiring board and a pair of side surfaces arranged on both the sides of the bottom surface and extending in the direction crossing the bottom surface; lead pins serving as conductors between the optical semiconductor device and the wiring board, each of the lead pins having a base end portion fixed at the side surface of the package and extending from this base end portion to the outside of the package; and a fixing region formed on the side surface of the package, in the fixing region, the base end portion of the lead pin being fixed to the position apart from the bottom surface of the package, thereby allowing the part of the lead pin lower than the base end portion to be detachable from the side surface of the package.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific example, while indicating preferred embodiment of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.